The field of this invention includes methods and equipment for measuring fabricated plate structures. Sheet metal and other structural plate products are conventionally cut to size and shape. Apertures in the plate are punched or otherwise created. Such processing proceeds according to predetermined design considerations. Quality control requires that the finished plates be remeasured to confirm the accuracy of their length, width, precise location of the apertures, and squareness.
Heretofore, it has been a practice in such quality control operations to utilize a table surface having an elongated slot extending at right angles from a straight gauge means. A movable carriage conveys a protruding pin in the slot. A suitable electronic measuring device is associated with the pin and a digital display.
A plate having a straight edge is abutted against the straight gauge means (hereafter stop) after the pin has been moved longitudinally in the slot to provide space between the pin and the stop to permit the plate to rest on the table surface. By bringing the pin to the edge of the plate opposite to the stop, and actuating the measuring device, the precise length of the plate can be confirmed.
If there are one or more apertures in the plate that need to have their locations verified, the plate must be tilted upward so the pin can be moved under the plate and inside the aperture. The plate is laid back flat on the table surface to take the desired measurement. Having to raise the plate for such measurements is time-consuming, hazardous and laborious for the user.
U.S. Pat. No. Re. 34,078 brought an improvement to the art of measuring plates with a selectively retractable pin in the slot of a measuring table. This improvement made the measuring table a more powerful, convenient tool for industrial quality control. However, some types of dimensional conformities are still difficult to verify on a conventional retractable pin measuring tables without repositioning and measuring the plate several times. For these reasons, squareness of plate edges is difficult to verify on retractable pin measuring tables.
Therefore, it is a principal object of this invention to provide a convenient and economical method and means for measuring the squareness of plate edges on a measuring table.
It is a further object of this invention to provide table attachments for measuring the squareness of plate edges.
It is a further object of this invention to provide squareness checking attachments which allow the existing pin, slot and digital readout of a conventional measuring table to be utilized.
It is a further object of this invention to provide a gauge generating a digital signal indicative of squareness capable of being processed by either the gauge itself or an existing digital readout on the table.
It is a further object of this invention to provide a measuring device which minimizes the number of measurements required on the measuring table to verify squareness.
It is a further object of this invention to provide a method of measure squareness which is quickly completable.
It is further an object of this invention to provide attachments for performing additional functions on a measuring table so that squareness can be conveniently measured.
It is further an object of this invention to provide attachments for measuring squareness on a measuring table so that the handling of plates is minimized.
It is further an object of this invention to provide attachments for measuring squareness on a measuring table whereby off-table measurements are avoided.
These and other objects will be apparent to those skilled in the art.